Electrical power steering device

ABSTRACT

A stator is disposed inside a motor case having a cylindrical shape. A winding wire is wound around the stator. A rotor is rotatably disposed inside the stator. A shaft is disposed in a rotational center of the rotor. A first plate covers one side of the motor case. The first plate rotatably supports one end portion of the shaft. A second plate has an insert hole extending in a thickness direction of the second plate. The second plate covers an other side of the motor case and rotatably supports an other end portion of the shaft. A wire extending portion has one end electrically connected to the winding wire. The wire extending portion extends from the winding wire and is inserted into the insert hole. A controller is disposed on a side of the second plate opposite to the motor case. The controller includes a substrate and is electrically connected to an other end of the wire extending portion at a side of the substrate opposite to the second plate to control energization to the winding wire.

CROSS REFERENCE TO RELATED APPLICATION

This application is a divisional application of application Ser. No.14/617,055, filed on Feb. 9, 2015 which is based on and incorporatesherein by reference Japanese Patent Application No. 2014-28498 filed onFeb. 18, 2014, the entire contents of each of which are incorporatedherein.

TECHNICAL FIELD

The present disclosure relates to a rotational electric machineintegrally having a motor and a controller.

BACKGROUND

Conventionally, a rotational electric machine integrally having a motorand a controller for controlling energization to a winding wire of themotor has been used. For example, a Patent Literature (JP 2011-10408 A)discloses a rotational electric motor having (i) a plate that covers oneend of a motor case having a cylindrical shape, and (ii) a controllerthat is disposed on a side of the plate opposite to the motor case. Inthe rotational electric machine of the Patent Literature, the windingwire and the controller are electrically connected to each other througha wire extending portion. The wire extending portion is inserted into aninsert hole formed in the plate that covers the one end of the motorcase.

According to the study by inventors of the present disclosure, in therotational electric machine of the Patent Literature, one end of thewire extending portion opposite to the winding wire is connected to asubstrate of the controller on a side of the substrate close to theplate (i.e., a side facing the plate). Thus, a work space to connect thewire extending portion to the controller is needed on the side of thesubstrate close to the plate. Accordingly, the size of the rotationalelectric machine including the controller may be increased.

Further, in the rotational electric machine of the Patent Literature,sputtering, a solder ball or the like, which is generated whenelectrically connecting the wire extending portion to the controller,may adhere to components on the side of the substrate close to the plateinside the rotational electric machine. Hence, it may be difficult toremove metallic foreign matters, such as sputtering or solder balls. Asa result, a short circuit fault may occur inside the rotational electricmachine.

Furthermore, a plurality of insert holes are formed in the plate, andthe wire extending portions are inserted into the respective insertholes. Thus, the wire extending portions are electrically connected tothe controller at plural positions on the controller in acircumferential direction of the plate. As such, the above-mentioneddisadvantages may be prominently exhibited, and the number of steps forforming the insert holes in the plate and for electrically connectingthe wire extending portion to the controller may be increased. Further,the risk of entry of a foreign matter into the motor case through theinsert holes may be also increased.

SUMMARY

It is an objective of the present disclosure to provide a rotationalelectric machine having a small size while being easily manufactured.

In an aspect of the present disclosure, a rotational electric machineincluding a motor, a first plate, a second plate, a wire extendingportion and a controller.

The motor includes a motor case, a stator, a winding wire, a rotor and ashaft. The stator is disposed inside the motor case. The winding wire iswound around the stator. The rotor is rotatably disposed inside thestator. The shaft is disposed in a rotational center of the rotor.

The motor includes a motor case, a stator, a winding wire, a rotor and ashaft. The first plate covers one side of the motor case and rotatablysupports one end portion of the shaft. The second plate has an inserthole extending in a thickness direction of the second plate. The secondplate covers an other side of the motor case and rotatably supports another end portion of the shaft. The wire extending portion has one endelectrically connected to the winding wire. The wire extending portionextends from the winding wire and is inserted into the insert hole.

The controller is disposed on a side of the second plate opposite to themotor case. The controller includes a substrate. The controller iselectrically connected to an other end of the wire extending portion ata side of the substrate opposite to the second plate or at thesubstrate, and controls energization to the winding wire.

According to the aspect of the present disclosure, the wire extendingportion that is connected to the winding wire is inserted into theinsert hole of the second plate, and the other end of the wire extendingportion is electrically connected to the controller at the side of thesubstrate opposite to the second plate or at the substrate. Thus, thereis no need to form a work space at a side of the substrate close to thesecond plate so as to electrically connect the other end of the wireextending portion to the controller. As a result, it is possible tosuppress an increase in the size of the rotational electric machine thatintegrally has the motor and the controller.

Further, the other end of the wire extending portion is electricallyconnected to the controller at the side of the substrate opposite to thesecond plate or at the substrate. Thus, it is possible to suppresssputtering or solder balls to adhere to components at a side of thesubstrate close to the second plate inside the rotational electricmachine. Therefore, metallic foreign matters such as sputtering orsolder balls can be easily removed. As a result, it is possible toeasily manufacture the rotational electric machine, in which theoccurrence of a short circuit fault inside the rotational electricmachine can be suppressed.

BRIEF DESCRIPTION OF THE DRAWINGS

The disclosure, together with additional objectives, features andadvantages thereof, will be best understood from the followingdescription, the appended claims and the accompanying drawings, inwhich:

FIG. 1 is a cross-sectional view schematically illustrating a rotationalelectric machine;

FIG. 2 is a cross-sectional view taken along II-II line in FIG. 1;

FIG. 3 is a circuit configuration of the rotational electric machine;

FIG. 4 is a portion of a manufacturing process of the rotationalelectric machine;

FIG. 5 is a portion of a manufacturing process of the rotationalelectric machine;

FIG. 6 is a cross-sectional view schematically illustrating anotherrotational electric machine; and

FIG. 7 is a cross-sectional view schematically illustrating furtheranother rotational electric machine.

DETAILED DESCRIPTION

A plurality of embodiments of the present disclosure will be describedhereinafter referring to drawings. In the embodiments, a part thatcorresponds to a matter described in a preceding embodiment may beassigned with the same reference numeral, and redundant explanation forthe part may be omitted. When only a part of a configuration isdescribed in an embodiment, another preceding embodiment may be appliedto the other parts of the configuration. The parts may be combined evenif it is not explicitly described that the parts can be combined. Theembodiments may be partially combined even if it is not explicitlydescribed that the embodiments can be combined, provided there is noharm in the combination.

(First Embodiment)

FIGS. 1 and 2 illustrate a rotational electric machine according to thefirst embodiment. As shown in FIG. 3, the rotational electric machine 10is used as a driving part for an electric power steering device 1 thatis mounted to a vehicle. The rotational electric machine 10 is providedsuch that an end portion (output end 26) of a shaft 25 of a motor 20, asdescribed below, engages a gear 3 of a gear box attached to a columnshaft 2. The rotational electric machine 10 generates an assisting forcefor steering of the vehicle. Specifically, the rotational electricmachine 10 generates the assisting force by driving the motor 20 in aforward or backward direction based on a torque signal output from atorque sensor 5 that detects a steering torque of a steering wheel 4, avehicle speed signal from a CAN (Controller Area Network (not shown)),or the like. As described above, in the present embodiment, a columnassist type electric power steering device is used as the electric powersteering device 1.

As shown in FIG. 1, the rotational electric machine 10 includes themotor 20, a magnet 27, a first plate 30, a second plate 40, a pluralityof wire extending portions 11, a controller 50, a plurality of terminalmembers 12, a cover 70, a connector 80, a connector terminal 81, a cap90, or the like.

The motor 20 includes a motor case 21, a stator 22, a winding wire 23, arotor 24, the shaft 25, or the like.

The motor case 21 is formed into a cylindrical shape and is made ofmetal, such as aluminum.

The stator 22 is formed into a substantially annual shape and is madeof, for example, a laminated steel plate. The stator 22 is fixed insidethe motor case 21.

The winding wire 23 is made of metal, such as copper, and is woundaround the stator 22. In the present embodiment, the winding wire 23corresponds to a U-phase, a V-phase and a W-phase.

The rotor 24 is formed into a substantially columnar shape and is madeof a laminated steel plate, as with the stator 22. The rotor 24 isrotatably disposed inside the stator 22. A plurality of magnets (notshown) are disposed on an outer wall of the rotor 24. The magnets havean N-pole or an S-pole and the N-pole magnet and the S-pole magnet arearranged alternately with given intervals in a circumferential directionof the rotor 24.

The shaft 25 is linearly formed and is made of, for example, metal. Theshaft 25 is disposed in a rotational center of the rotor 24.

The shaft 25 has the output end 26 at one end portion of the shaft 25.The output end 26 engages the gear 3 of the electric power steeringdevice 1. The shaft 25 has the magnet 27 on the other end portion of theshaft 25. The magnet 27 generates magnetic flux. The magnet 27 mayprovide “magnetic flux generator”.

The first plate 30 is formed into a plate shape and is made of metal,such as aluminum. The first plate 30 is integrally formed with the motorcase 21 and the first plate 30 covers one side of the motor case 21. Ashaft hole 31 is formed at a center of the first plate 30. A bearingmember 32 is disposed in the shaft hole 31. The bearing member 32rotatably supports one end portion of the shaft 25. That is, the one endportion of the shaft 25 is rotatably supported by the first plate 30through the bearing member 32.

The second plate 40 is formed into a plate shape and is made of metal,such as aluminum. The second plate 40 is separately formed from themotor case 21, and the second plate 40 covers the other side of themotor case 21. The motor case 21 is fully in contact with the secondplate 40 in the circumferential direction of the motor case 21. A shafthole 41 is formed at a center of the second plate 40. A bearing member42 is formed in the shaft hole 41. The bearing member 42 rotatablysupports the other end portion of the shaft 25. That is, the other endportion of the shaft 25 is rotatably supported by the second plate 40through the bearing member 42.

As described above, the one end portion of the shaft 25 is rotatablysupported by the first plate 30 and the other end portion of the shaft25 is rotatably supported by the second plate 40. As such, the rotor 24is rotatable inside the stator 22 relative to the stator 22.

An annular groove is formed on an outer wall of the second plate 40facing an inner wall of the motor case 21. A sealing member 43 made ofrubber and having an annular shape is disposed in the annular groove(refer to FIG. 1). The sealing member 43 is compressed between thesecond plate 40 and the motor case 21 in a state where the second plate40 covers the other side of the motor case 21. Accordingly, a spacebetween the second plate 40 and the motor case 21 is maintained in anair-tightly or liquid-tightly sealed state by the sealing member 43.

As shown in FIGS. 1 and 2, an insert hole 44 and a hole 45 are formed inthe second plate 40 at a position radially inward of the sealing member43. The insert hole 44 and the hole 45 extend in a thickness directionof the second plate 40. An inside space of the motor case 21 iscommunicated with an outside space at a side of the second plate 40opposite to the motor case 21 through the insert hole 44 and the hole 45in a state where the second plate 40 covers the other side of the motorcase 21.

A recessed portion 46 is formed on a surface of the second plate 40opposite to the motor case 21, and the recessed portion 46 is recessedfrom the surface of the second plate 40 toward the motor case 21.

Each wire extending portion 11 is linearly formed and is made of metal,such as copper. The wire extending portion 11 has one end electricallyconnected to the winding wire 23. The wire extending portion 11 extendsfrom the winding wire 23 and is inserted into the insert hole 44. Theone end of the wire extending portion 11 is electrically connected tothe winding wire 23 by welding, soldering, or the like. The wireextending portion 11 is disposed not to be in contact with the secondplate 40 (the insert hole 44). Further, an outer wall of the wireextending portion 11 is covered with an insulating film.

As shown in FIG. 2, the rotational electric machine 10 of the presentembodiment has six wire extending portions 11. A pair of wire extendingportions 11 corresponds to each phase (U, V or W-phase) of the windingwire 23. The number of the insert hole 44 is one. Thus, six wireextending portions 11 are inserted into only the insert hole 44.

The controller 50 is disposed on a side of the second plate 40 oppositeto the motor case 21. As shown in FIGS. 1 and 3, the controller 50includes a first capacitor 51, a choke coil 52, a power module 53 as aninverter circuit 1, a power module 54 as an inverter circuit 2, secondcapacitors 55, a substrate 60, a custom IC (ASIC) 61, a rotational anglesensor 62, a control IC 63, or the like.

As shown in FIG. 3, electric power is supplied to the controller 50 froma battery 6. The first capacitor 51 and the choke coil 52 constitute afilter circuit and suppress noise of the rotational electric machine 10to transmit to other devices that commonly use the battery 6. Also, thechoke coil 52 is connected between the battery 6 and the power modules53 and 54 in series and suppresses power fluctuation.

The power module 53 is a semiconductor module in which switchingelements 501 to 506, power supply relays 507 and 508, shunt resistors509, or the like, are integrally formed by being covered with a sealingbody (not shown) made of, for example, resin.

The switching elements 501 to 506 constitute a MOSFET(metal-oxide-semiconductor field-effect transistor) that is a type of afield effect transistor. Each switching element 501 to 506 is turnedON/OFF between a source and a drain according to a gate voltage.

The drains of the switching elements 501 to 503 on an upper arm areconnected to the battery 6, and the sources thereof are connected to thedrains of the corresponding switching elements 504 to 506 on a lowerarm. The sources of the switching elements 504 to 506 on the lower armare connected to a circuit ground. The connecting points between theswitching elements 501 to 503 and the corresponding switching elements504 to 506 are electrically connected to the motor 20.

As with the switching elements 501 to 506, the power supply relays 507and 508 constitute a MOSFET. The power supply relays 507 and 508 arepositioned between the switching elements 501 to 506 and the choke coil52, and cut off a current toward the motor 20 through the switchingelements 501 to 506 when system failure occurs.

Each shunt resistor 509 is electrically connected between the respectiveswitching elements 504 to 506 and the circuit ground. A current flowingthrough the motor 20 can be detected by detecting a voltage or a currentapplied to the shunt resistor 509.

The description as to the power module 54 is omitted since theconfiguration of the power module 54 is the same as that of the powermodule 53 as described above. The power module 53, 54 may provide“semiconductor module”.

Each second capacitor 55 is connected between a wiring on a side of thecorresponding switching elements 501 to 503 close to the battery 6 andthe circuit ground. In other words, the second capacitors 55 areconnected to the switching elements 501 to 506 in parallel. The secondcapacitor 55 stores electric charges and supports the power supply tothe switching elements 501 to 506. Further, the second capacitor 55absorbs a ripple current generated due to current switching.

The custom IC 61 is a semiconductor integrated circuit including aregulator 64, a rotational angle signal amplifier 65, a detected voltageamplifier 66 or the like.

The regulator 64 is a stabilizing circuit to stabilize electric powerfrom the battery 6. The regulator 64 stabilizes electric power suppliedto each element. For example, a microcomputer 67 as described belowoperates with a stabilized voltage (e.g., 5V) by the regulator 64.

A signal is input into the rotational angle signal amplifier 65 from therotational angle sensor 62. The rotational angle sensor 62 is a magneticflux detecting element, such as a Hall IC. The rotational angle sensor62 is disposed on the substrate 60 at a position close to the magnet 27arranged on the shaft 25 of the motor 20, more specifically, at aposition on an axial line of the shaft 25 (refer to FIG. 1). Therotational angel sensor 62 detects magnetic flux generated by the magnet27, i.e., detects a change of the magnetic flux (magnetic field) aroundthe rotational angle sensor 62. The rotational angle sensor 62 transmitsthe detected signal to the rotational angle signal amplifier 65 as asignal related to a rotational angle of the motor 20 (the rotor 24). Therotational angle signal amplifier 65 amplifies the signal related to arotational angle of the motor 20 and transmits the amplified signal tothe microcomputer 67 as described below. The rotational angle sensor 62may provide “flux detector”.

The detected voltage amplifier 66 detects a voltage between both ends ofthe shunt resistor 509 and amplifies the detected voltage. The amplifiedvoltage is transmitted to the microcomputer 67 from the detected voltageamplifier 66.

The control IC 63 is a semiconductor integrated circuit including themicrocomputer 67, pre-drivers 68 and 69, or the like.

The microcomputer 67 is a small computer including a CPU as acalculator, a ROM and a RAM, as storage, or the like. The microcomputer67 executes a variety of processes at the CPU according to a variety ofprograms stored in the ROM.

The signal related to the rotational angle of the motor 20 from therotational angle signal amplifier 65, a voltage between both ends of theshunt resistor 509 from the detected voltage amplifier 66, a steeringtorque signal, and the vehicle speed signal from the CAN are input intothe microcomputer 67. The microcomputer 67 controls the power module 53through the pre-driver 68 based on the rotational angle of the motor 20.Specifically, the microcomputer 67 changes the gate voltage of theswitching elements 501 to 506 by the pre-driver 68 to switch ON/OFF ofthe switching elements 501 to 506, thereby controlling the power module53.

Further, the microcomputer 67 controls the power module 53 based on thevoltage between both ends of the shunt resistor 509 that is input fromthe detected voltage amplifier 66 such that a wave form of the currentsupplied to the motor 20 (the winding wire 23) becomes a sine wave. Aswith the power module 53, the microcomputer 67 also controls the powermodule 54 through the pre-driver 69.

The microcomputer 67 generates a pulse signal by PVM control through thepre-drivers 68 and 69 based on the signals from the rotational anglesensor 62, the torque sensor 5, and the shunt resistors 509, and thevehicle speed signal from the CAN so as to assist a driver in steeringusing the steering wheel 4 according to vehicle speed. The pulse signalis output to two inverter circuit systems constituted by the powermodule 53 and the power module 54. The ON-OFF switching operation of theswitching elements 501 to 506 is controlled based on the pulse signalgenerated by the microcomputer 67. As a result, a sinusoidal currenthaving a different phase flows through each phase of the winding wire 23of the motor 20, and thus a rotating magnetic field is generated.Accordingly, the rotor 24 and the shaft 25 integrally rotate due to therotating magnetic field. Hence, a driving force is output from theoutput end 26 to the gear 3 of the column shaft 2 by the rotation of theshaft 25, whereby the steering by a driver through the steering wheel 4is assisted.

As described above, the controller 50 has two different power modulesystems (the power modules 53 and 54) and controls energization to thewinding wire 23. Each power module system has the U-phase, the V-phaseand the W-phase. The power modules 53 and 54 (the switching elements 501to 506) generate heat during operation (i.e., switching of the switchingelements 501 to 506).

The substrate 60 is a printed circuit board, such as FR-4, that is madeof, for example, glass fiber and epoxy resin. As shown in FIG. 1, thesubstrate 60 is disposed on a side of the second plate 40 opposite tothe motor case 21, and the substrate 60 is in parallel to the secondplate 40. In the present embodiment, the substrate 60 is fixed to thesecond plate 40 and is in contact with the second plate 40.

The first capacitor 51, the choke coil 52, the second capacitor 55, thecustom IC 61, the control IC 63, or the like are mounted on one surfaceof the substrate 60 opposite to the second plate 40. The rotationalangle sensor 62, the power modules 53 and 54 are mounted on the othersurface (a surface) of the substrate 60 close to (i.e., facing) thesecond plate 40. The rotational angle sensor 62 is positioned on theaxial line of the shaft 25. The power modules 53 and 54 are housedinside the recessed portion 46 of the second plate 40.

A heat transfer member 47 is disposed between the power modules 53 and54 and the recessed portion 46. The heat transfer member 47 is formedby, for example, an insulation radiating heat seat and a thermal grease.The insulation radiating heat seat is an insulating seat with a lowthermal resistance including, for example, silicon. The thermal greaseis a gel grease with a low thermal resistance having, for example, asilicon substrate. According to this configuration, heat duringoperation of the power modules 53 and 54 is transferred to the secondplate 40 and the motor case 21 through the heat transfer member 47 andthen is radiated rom the second plate 40 and the motor case 21.

The terminal members 12 are linearly formed and made of metal, such ascopper. Each terminal member 12 has one end electrically connected to aprinted wiring on the substrate 60 of the controller 50. The printedwiring is electrically connected to the connecting points between theswitching elements 501 to 503 on the upper arm and the correspondingswitching elements 504 to 506 on the lower arm.

In the present embodiment, six terminal members 12 corresponding to sixwire extending portions 11 are provided. Each terminal member 12 isparallel to the corresponding wire extending portion 11. The other endof the wire extending portion 11 opposite to the winding wire 23 iselectrically connected to the other end of the terminal member 12opposite to the substrate 60 by, for example, soldering or welding(refer to FIG. 1). As described above, the other end of the wireextending portion 11 is electrically connected to the controller 50 at aside of the substrate 60 opposite to the second plate 40.

The power modules 53 and 54 and the winding wire 23 are electricallyconnected each other through the terminal members 12 and the wireextending portions 11, whereby electric power is supplied to the windingwire 23 through the power modules 53 and 54, the terminal members 12 andthe wire extending portions 11.

The cover 70 is formed into a disk-like shape and is made of, forexample, resin. The cover 70 has an opening 71 in a bottom of the cover70, and an outside and an inside of the cover 70 are in communicationwith each other through the opening 71. The cover 70 is disposed on theside of the second plate 40 close to the controller 50, i.e., on theside of the second plate 40 opposite to the motor case 21, and coversthe controller 50 therein. The other end of the wire extending portion11 and the other end of the terminal member 12, i.e., a connectingportion of the wire extending portion 11 and the terminal member 12, arepositioned in the opening 71. An outer circumferential periphery of thecover 70 is fixed to the second plate 40 with a plurality of screws 72.Thus, the cover 70 is attached to the second plate 40. The cover 70 canprotect the controller 50 from an external impact, dust, or liquid, suchas water.

The connector 80 is integrally formed with the cover 70 and is made of,for example, resin. The connector 80 has a cylindrical shape and extendsfrom a center of the cover 70 in a direction away from the controller50. The connector terminal 81 is made of metal, such as copper. One endof the connector terminal 81 is positioned inside the connector 80 andthe other end of the connector terminal 81 is electrically connected tothe substrate 60 of the controller 50. The other end of the connectorterminal 81 is electrically connected to the substrate 60 through athrough hole 601 formed in the substrate 60 at a position correspondingto the hole 45 of the second plate 40.

A harness 7 is connected to the connector 80. Therefore, the harness 7is electrically connected to the one end of the connector terminal 81. Acurrent from the battery 6, a signal from the CAN and a signal from thetorque sensor 5 flow through the harness 7, and thus are supplied to thecontroller 50 through the connector 80 and the connector terminal 81.

The cap 90 is disposed in the opening 71 of the cover 70. The cap 90includes a cylinder 91, a plate portion 92, a ventilation portion 93, orthe like. The cylinder 91 is formed into a cylindrical shape and is madeof, for example, resin. The plate portion 92 is made of, for example,resin and is formed integrally with the cylinder 91. The plate portion92 covers one side of the cylinder 91. The ventilation portion 93 ismade from a film, which is manufactured by stretching, for example,polytetrafluoroethylene, and a moisture-permeable waterproof material,which has a microporous property by compounding a polyurethane polymer.The ventilation portion 93 is disposed in the plate portion 92 and theventilation portion 93 allows air to flow between the inside and theoutside of the cap 90 (the cylinder 91) and prohibits liquid fromflowing between the inside and the outside of the cap 90 (the cylinder91).

The cap 90 is disposed on the cover 70 and the other end of the wireextending portion 11 and the other end of the terminal member 12, i.e.,the connecting portion between the wire extending portion 11 and theterminal member 12, are positioned inside the cylinder 91. Further, thecap 90 closes the opening 71. As a result, the other end of the wireextending portion 11 and the other end of the terminal member 12 arecovered with the cap 90.

Next, a method for manufacturing the rotational electric machine 10according to the present embodiment will be described below. Themanufacturing method includes steps as below.

(Motor Assembling Step)

As shown in FIG. 4, the winding wire 23 is wound around the stator 22and the stator 22 is fixed inside the motor case 21 that is integrallyformed with the first plate 30. The bearing member 32 is disposed in theshaft hole 31 of the first plate 30. The one end portion of the shaft25, to which the rotor 24 is attached, is inserted into the bearingmember 32. The output end 26 is attached to the one end portion of theshaft 25. The other end portion of the shaft 25 is inserted into thebearing member 42. The magnet 27 is attached to the other end portion ofthe shaft 25. The one end of each wire extending portion 11 iselectrically connected to the winding wire 23.

(Controller Assembling Step)

As shown in FIG. 4, a variety of electric components are amounted on thesubstrate 60 and the one end of each terminal member 12 is electricallyconnected to the substrate 60. The heat transfer member 47 is disposedinside the recessed portion 46 of the second plate 40. The substrate 60is fixed to the second plate 40 such that the rotational angle sensor 62is positioned at a center of the shaft hole 41 and the power modules 53and 54 are housed inside the recessed portion 46. The cover 70 is fixedto the second plate 40 with the screws 72 such that the one end of eachterminal member 12 is positioned in the opening 71, and the other end ofthe connector terminal 81 is inserted into the through hole 601 of thesubstrate 60. The other end of the connector terminal 81 is electricallyconnected to the printed wiring of the substrate 60 at the through hole601 using a soldering tool (not shown) that is inserted through the hole45. The sealing member 43 is disposed inside the groove on the outerwall of the second plate 40.

(Joining Step)

As shown in FIGS. 4 and 5, the motor case 21 is joined with the secondplate 40 in a state where the wire extending portions 11 are insertedinto the insert hole 44, and the bearing member 42 is press-fitted intothe shaft hole 41. As a result, the other ends of six terminal members12 are positioned close to the other ends of six wire extending portions11 in the opening 71.

(Terminal Member Connecting Step)

The other end of the terminal member 12 is electrically connected to theother end of the corresponding wire extending portion 11 using thesoldering tool from an outside of the cover 70.

(Cap Assembling Step)

As shown in FIGS. 1 and 5, the cap 90 is fitted into the opening 71 ofthe cover 70 such that the connecting portion of the other end of eachterminal member 12 and the other end of each wire extending portion 11is positioned inside the cylinder 91.

As described above, according to the present embodiment, the motor 20includes the motor case 21, the stator 22, the winding wire 23, therotor 24 and the shaft 25. The stator 22 is disposed inside the motorcase 21 having the cylindrical shape. The winding wire 23 is woundaround the stator 22. The rotor 24 is rotatably disposed inside thestator 22. The shaft 25 is disposed in the rotational center of therotor 24.

The first plate 30 covers the one side of the motor case 21 androtatably supports the one end portion of the shaft 25. The second plate40 has the insert hole 44 extending in the thickness direction of thesecond plate 40. The second plate 40 covers the other side of the motorcase 21 and rotatably supports the other end portion of the shaft 25.The wire extending portion 11 has the one end electrically connected tothe winding wire 23. The wire extending portion extends from the windingwire 23 and is inserted into the insert hole 44.

The controller 50 is disposed on the side of the second plate 40opposite to the motor case 21. The controller 50 includes a substrate60, and the controller 50 is electrically connected to the other end ofthe wire extending portion 11 at the side of the substrate 60 oppositeto the second plate 40, whereby the controller 50 controls energizationto the winding wire 23.

As described above, the wire extending portion 11 connected to thewinding wire 23 is inserted into the insert hole 44 and the other end ofthe wire extending portion 11 is electrically connected to thecontroller 50 at the side of the substrate 60 opposite to the secondplate 40. Accordingly, there is no need to form a work space at the sideof the substrate 60 close to the second plate 40 so as to electricallyconnect the other end of the wire extending portion 11 to the controller50. As a result, an increase in the size of the rotational electricmachine 10, which integrally has the motor 20 and the controller 50, canbe suppressed.

Further, since the other end of the wire extending portion 11 iselectrically connected to the controller 50 at the side of the substrate60 opposite to the second plate 40, sputtering, a solder ball, or thelike, which are generated when electrically connecting the other end ofthe wire extending portion 11 to the controller 50, can be suppressed toadhere to components on the side of the substrate 60 close to the secondplate 40. As such, it is possible to easily remove metallic foreignmatters, such as sputtering or solder balls. Therefore, an occurrence ofa short circuit fault can be suppressed in the rotational electricmachine 10, while easily manufacturing the rotational electric machine10.

According to the present embodiment, the number of the insert hole 44that is formed in the second plate 40 is one. Thus, the number of theprocesses for forming the insert hole 44 and for electrically connectingthe other end of the wire extending portion 11 to the controller 50 canbe reduced. Further, the risk of entry of a foreign matter into themotor case 21 through the insert hole 44 can be suppressed.

According to the present embodiment, the cover 70 is disposed on theside of the second plate 40 opposite to the motor case 21 (i.e., theside close to the controller 50) to cover the controller 50. As such,the controller 50 can be protected from an external impact, dust, orliquid, such as water, by the cover 70.

According to the present embodiment, the connector 80 is integrallyformed with the cover 70, and the harness 7 is connected to theconnector 80 to supply electric power to the winding wire 23. Theconnector terminal 81 has the one end positioned inside the connector 80and electrically connected to the harness 7. The connector terminal 81has the other end electrically connected to the controller 50 at thethrough hole 601. The second plate 40 has the hole 45 at the positioncorresponding to the other end of the connector terminal 81. The hole 45provides an inner connecting work space where the other end of theconnector terminal 81 is electrically connected to the controller 50using, for example, a soldering tool. Accordingly, the other end of theconnector terminal 81 can be electrically connected to the controller 50using the hole 45 after the controller 50 and the cover 70 are attachedto the second plate 40, for example.

According to the present embodiment, the terminal member 12 extends fromthe controller 50 in the direction away from the second plate 40. Theterminal member 12 has the one end electrically connected to thecontroller 50 and the other end electrically connected to the other endof the wire extending portion 11. Therefore, the other end of the wireextending portion 11 can be electrically connected to the controller 50through the terminal member 12 at a position further away from thesecond plate 40.

According to the present embodiment, the cover 70 has the opening 71 inwhich the other end of the wire extending portion 11 and the other endof the terminal member 12 are positioned. Thus, the other end of thewire extending portion 11 and the other end of the terminal member 12can be electrically connected to each other in the opening 71 after themotor case 21, the second plate 40, the controller 50 and the cover 70are assembled, for example. Accordingly, a work space for connecting theother end of the wire extending portion 11 to the other end of theterminal member 12 is not required inside the rotational electricmachine 10. Further, it is possible to suppress sputtering or solderballs, which is generated when electrically connecting both other endsof the wire extending portion 11 and the terminal member 12, to adhereto an inside of the rotational electric machine 10.

According to the present embodiment, the cap 90 covers the other end ofthe wire extending portion 11 and the other end of the terminal member12 The cap 90 closes the opening 71. Hence, the connecting portion ofthe other end of the wire extending portion 11 and the other end of theterminal member 12 can be protected by the cap 90, and entry of dust orliquid, such as water, into the cover 70 through the opening 71 can besuppressed.

According to the present embodiment, the cap 90 includes the ventilationportion 93 that allows gas to flow between the inside and the outside ofthe cap 90 and prohibits liquid from flowing between the inside and theoutside of the cap 90. The ventilation portion 93 is made of, forexample, a moisture-permeable waterproof material. Therefore, it ispossible to suppress liquid, such as water, to flow into the cover 70through the opening 71 while properly maintaining humidity inside thecover 70.

According to the present embodiment, the controller 50 includes thepower modules 53 and 54 that are mounted on the substrate 60. The powermodules 53 and 54 control energization to the winding wire 23. That is,two inverter circuit systems are provided in the present embodiment. Assuch, if there is an abnormality in one inverter circuit system, therotational electric machine 10 can still operate by the other invertercircuit system.

It should be noted that, since two inverter circuit systems are providedin the present embodiment, a heat amount generated during operation ofthe rotational electric machine 10 may tend to be relatively large.Further, since the rotational electric machine 10 is a three-phase drivetype having two inverter circuit systems, the number of electricalconnecting points of the winding wire 23 (the wire extending portion 11)and the controller 50 may tend to be large. However, according to thepresent embodiment, the number of the insert hole 44, which is formed inthe second plate 40, is only one. Hence, the number of the processes forelectrically connecting the wire extending portion 11 to the controller50 can be reduced while having the plural inverter circuit systems.Further, the risk of entry of a foreign matter into the motor case 21through the insert hole 44 can be also suppressed.

According to the present embodiment, the power modules 53 and 54 areamounted on the surface of the substrate 60 close to (i.e., facing) thesecond plate 40. Thus, heat generated during operation from the powermodules 53 and 54 can be efficiently transferred to the second plate 40and the heat can be radiated from the second plate 40.

According to the present embodiment, the magnet 27 is disposed on theother end portion of the shaft 25 and generates magnetic flux. Thecontroller 50 includes the rotational angle sensor 62 that is mounted onthe substrate 60. The rotational angle sensor 62 detects the magneticflux generated by the magnet 27. The substrate 60 is disposed on thesecond plate 40. That is, the rotational angle sensor 62 is mounted onthe substrate 60 that is disposed on the second plate 40 rotatablysupporting the other end portion of the shaft 25. Accordingly, therotational angle sensor 62 can be precisely positioned with respect tothe magnet 27 disposed on the other end portion of the shaft 25.

According to the present embodiment, the second plate 40 is formedseparately from the motor case 21, and the second plate 40 and the motorcase 21 are made of metal. The motor case 21 is fully in contact withthe second plate 40 in the circumferential direction of the motor case21. Therefore, heat from the power modules 53 and 54 can be efficientlytransferred to the motor case 21 through the second plate 40, and theheat can be radiated from the motor case 21.

According to the present embodiment, the sealing member 43 is disposedbetween the second plate 40 and the motor case 21 to air-tightly orliquid-tightly seal between the second plate 40 and the motor case 21.As a result, entry of dust or liquid, such as water, into the motor case21 through a space between the second plate 40 and the motor case 21 canbe suppressed.

According to the present embodiment, the first plate 30 is integrallyformed with the motor case 21, and the first plate 30 and the motor case21 are made of metal. Hence, the number of parts of the rotationalelectric machine 10 can be reduced. Also, heat generated from the powermodules 53 and 54 can be transferred to the first plate 30 through thesecond plate 40 and the motor case 21 and the heat can be radiated fromthe first plate 30.

(Second Embodiment)

FIG. 6 illustrates a rotational electric machine according to the secondembodiment. In the second embodiment, the shape of the wire extendingportion 11 and the cover 70 is different from that in the firstembodiment.

In the second embodiment, the other end of the wire extending portion 11is positioned at the through hole 602 of the substrate 60. The other endof the wire extending portion 11 is electrically connected to theprinted wiring of the substrate 60 at the through hole 602 bypress-fitting. That is, the controller 50 is electrically connected tothe other end of the wire extending portion 11.

In the second embodiment, the terminal member 12 described in the firstembodiment is eliminated. Further, the cover 70 does not have theopening 71 as described in the first embodiment. The cap 90 in the firstembodiment is also eliminated in the second embodiment.

Next, a method for manufacturing the rotational electric machineaccording to the second embodiment will be described below. Themanufacturing method includes steps as below.

(Motor Assembling Step)

Since the motor assembling step in the second embodiment is the same asin the first embodiment, the description of the step is omitted.

(Controller Assembling Step)

The heat transfer member 47 is disposed in the recessed portion 46 ofthe second plate 40. The substrate 60 is fixed to the second plate 40such that the rotational angle sensor 62 is positioned at the center ofthe shaft hole 41 and the power modules 53 and 54 are housed inside therecessed portion 46. Further, the cover 70 is fixed to the second plate40 with the screws 72 such that the other end of the connector terminal81 is inserted into the through hole 601 of the substrate 60. The otherend of the connector terminal 81 is electrically connected to theprinted wiring of the substrate 60 at the through hole 601 using asoldering tool (not shown) that is inserted through the hole 45. Thesealing member 43 is disposed inside the groove on the outer wall of thesecond plate 40.

(Joining Step)

The motor case 21 is joined with the second plate 40 in a state wherethe wire extending portion 11 is inserted into the insert hole 44, theother end of the wire extending portion 11 is inserted into a throughhole 602 formed in the substrate 60, and the bearing member 42 ispress-fitted into the shaft hole 41. In this way, the other ends of sixwire extending portions 11 are electrically connected to the printedwiring of the substrate 60 at the through hole 602 by press-fitting.

According to the second embodiment, the wire extending portion 11 thatis connected to the winding wire 23 is inserted into the insert hole 44of the second plate 40, and the controller 50 is electrically connectedto the other end of the wire extending portion 11 at the substrate 60(the through hole 602). Therefore, as with the first embodiment, thereis no need to form a work space at the side of the substrate 60 close tothe second plate 40 so as to electrically connect the other end of thewire extending portion 11 to the controller 50. As a result, an increasein the size of the rotational electric machine, which integrally has themotor 20 and the controller 50, can be suppressed.

According to the second embodiment, the other end of the wire extendingportion 11 is electrically connected to the controller 50 bypress-fitting. Thus, the wire extending portion 11 can be easilyconnected to the controller 50 compared to the first embodiment.Further, the number of parts of the rotational electric machine can beless than that in the first embodiment in which the terminal members 12and the cap 90 are provided. Further, in the second embodiment, there isno need to form the opening 71 in the cover 70 as with the case of thefirst embodiment, whereby the number of manufacturing process can bealso reduced in the second embodiment.

(Third Embodiment)

FIG. 7 shows a rotational electric machine according to the thirdembodiment. In the third embodiment, the shape of the motor case 21, thefirst plate 30 and the second plate 40 is different from that in thefirst embodiment.

In the third embodiment, the first plate 30 is separately formed fromthe motor case 21, and the first plate 30 covers the one side of themotor case 21. The motor case 21 and the first plate 30 are joined eachother such that the motor case 21 is fully in contact with the firstplate 30 in the circumferential direction of the motor case 21.

An annular groove is formed on an outer wall of the first plate 30 thatfaces the inner wall of the motor case 21. A sealing member 43 isdisposed in the annular groove (refer to FIG. 7). The sealing member 43is compressed between the first plate 30 and the motor case 21 in astate where the first plate 30 covers the one side of the motor case 21.Thus, a space between the first plate 30 and the motor case 21 isair-tightly or liquid-tightly sealed by the sealing member 43.

In the third embodiment, the second plate 40 is integrally formed withthe motor case 21 and the second plate 40 covers the other side of themotor case 21.

As described above, according to the third embodiment, the first plate30 is formed separately from the motor case 21, and the first plate 30and the motor case 21 are made of metal. The motor case 21 is fully incontact with the first plate 30 in the circumferential direction of themotor case 21. Accordingly, heat generated from the power modules 53 and54 can be efficiently transferred to the first plate 30 through themotor case 21, and the heat can be radiated from the first plate 30.

According to the third embodiment, the sealing member 43 is disposedbetween the first plate 30 and the motor case 21 to air-tightly orliquid-tightly seal between the first plate 30 and the motor case 21.Hence, it is possible to suppress dust or liquid, such as water, to flowinto the motor case 21 through a space between the first plate 30 andthe motor case 21.

According to the third embodiment, the second plate 40 is integrallyformed with the motor case 21, and the second plate 40 and the motorcase 21 are made of metal. Hence, the number of parts of the rotationalelectric machine can be reduced. Also, heat generated from the powermodules 53 and 54 can be transferred to the motor case 21 through thesecond plate 40, and the heat can be radiated from the motor case 21.

(Other Embodiments)

In a fourth embodiment, the number of the insert holes, into which thewire extending portion is inserted, may be more than one.

In a fifth embodiment, the cover may be eliminated.

In a sixth embodiment, the connector and the connector terminal may beeliminated. Further, the second plate may not have the hole thatprovides an inner connecting work space where the other end of theconnector terminal is electrically connected to the controller.

In a seventh embodiment, the ventilation portion may be configured byforming a plurality of micropores in the cap, for example. The cap maynot have the ventilation portion.

In an eighth embodiment, the number of the semiconductor modules (thepower modules) may be not only two but also one or more than two. Inother words, the rotational electric machine may have not only twoinverter systems but also one or more than two inverter systems. Thus,the number of the wire extending portions and the terminals may be notonly six but also other than six, respectively.

In the above-described embodiments, a plurality of switching elements501 to 506 and the power supply relays 507 and 508 are provided in eachpower module 53, 54. Alternatively, in a ninth embodiment, the powermodule may be configured by covering with a sealing body each of theplurality of switching elements and each power supply relay, or eachpair of the plurality of switching elements and the power supply relays.

In a tenth embodiment, the semiconductor module (the power module) maybe mounted on a surface of the substrate opposite to the second plate.The second plate may not have the recessed portion inside which thesemiconductor module is housed. The heat transfer member may not bedisposed in the recessed portion.

In an eleventh embodiment, the magnetic flux generator may be notprovided on the other end portion of the shaft. The controller may nothave the magnetic flux detector on the substrate.

In a thirteenth embodiment, at least one of the motor case, the firstplate or the second plate may be made of a material other than resin ormetal.

In a fourteenth embodiment, the sealing member may not be providedbetween the second plate or the first plate and the motor case.

In the above-described embodiment, the rotational electric machine hasthe winding wire of the three-phase type (U-phase, V-phase, W-phase). Ina fifteenth embodiment, the winding wire may have n-phase other thanthree.

In the above-described embodiment, the rotational electric machine isapplied to a column assist type electric power steering device. Whereas,in a sixteenth embodiment, the rotational electric machine may beapplied to a rack assist type electric power steering device in which anassist torque is applied to a rack shaft.

In a seventeenth embodiment, the rotational electric machine can be usedas not only the driver of the electric power steering device but also adriver for driving wheels of a HV vehicle or a driver for instrumentsthat are installed to a certain object other than a vehicle.

It should be noted that the present disclosure may not be only limitedto the above-described embodiments. The present disclosure may beapplied to other embodiment within the scope of the present disclosure.

What is claimed is:
 1. An electrical power steering device comprising: a motor that includes a motor case having a cylindrical shape, a stator disposed inside the motor case, a winding wire wound around the stator, a rotor rotatably disposed inside the stator, and a shaft disposed in a rotational center of the rotor, a magnet being arranged on an end portion of the shaft; a first plate that covers one side of the motor case, the first plate rotatably supporting one end portion of the shaft; a second plate covering a another side of the motor case and rotatably supporting another end portion of the shaft, the second plate including an insert hole extending in a thickness direction of the second plate, a first recessed portion formed on a side of the second plate opposite to the motor case, a second recessed portion formed on the side of the second plate opposite to the motor case, and a shaft hole portion; a wire extending portion that has one end electrically connected to the winding wire, the wire extending portion extending from the winding wire and being inserted into the insert hole; a controller that is disposed on the side of the second plate opposite to the motor case, the controller including a substrate, wherein the substrate includes a first surface that faces away from the second plate, a capacitor being disposed on the first surface, a second surface that faces toward the second plate, a plurality of semiconductor modules being disposed on the second surface, a rotational angle sensor arranged near the end portion of the shaft, and a throughhole, the wire winding portion being inserted through the throughhole, the second plate is configured to house the magnet of the shaft within the first recessed portion, house the semiconductor modules within the second recessed portion, and dissipate heat generated by the semiconductor modules, and the second recessed portion is formed within a surface of the second plate that faces toward the substrate.
 2. The electrical power steering device of claim 1, wherein a heat transfer member is disposed between the semiconductor modules and the second recessed portion.
 3. The electrical power steering device of claim 1, wherein the second plate rotatably supports the end portion of the shaft through a bearing, and the second plate extends along the thickness direction from a vicinity of the substrate to house at least a portion of the bearing.
 4. The electrical power steering device of claim 3, wherein the second plate includes a third recessed portion formed on a side of the second plate toward the motor case, and the bearing is at least partially housed within the third recessed portion.
 5. The electrical power steering device of claim 1, further comprising: a cover that is disposed on the side of the second plate opposite to the motor case to cover the controller; and a connector formed to protrude from the cover and extend in a direction away from the controller.
 6. The electrical power steering device of claim 1, wherein the rotational angle sensor is arranged on the second surface of the substrate to face the magnet.
 7. The electrical power steering device of claim 1, wherein the rotational angle sensor is coaxial with the magnet along an axial direction of the shaft.
 8. The electrical power steering device of claim 1, wherein the controller is disposed to abut the second plate, and the second plate includes a third recessed portion formed on a side of the second plate toward the motor case, a bearing of the shaft being at least partially housed within the third recessed portion. 